涡流脉冲热像检测中金属疲劳裂纹的生热分析

涡流脉冲热像技术是一种将电磁生热和红外热成像相结合的新型无损检测技术。针对金属疲劳裂纹生热研究不深入的问题,本文以含有贯穿的疲劳裂纹金属平板试件为研究对象,搭建了涡流脉冲热像检测实验系统,并建立了涡流脉冲热像有限元模型,分析了涡流脉冲热像检测中裂纹生热的规律。研究结果表明:在红外热像中,同一时刻越靠近裂纹根部的位置,温升的最大值越大;在激励过程中,裂纹区域的温升逐渐升高,当激励结束时,裂纹区域的温升则具有逐渐下降趋势,并且呈现先迅速后缓慢的下降速度。进一步揭示了裂纹尺寸对裂纹区域温升的影响。

Thermal Analysis of Metal Fatigue Cracks in Eddy Current Pulsed Thermography

Eddy current pulsed thermography(ECPT)is a new type of non-destructive testing method that combines electromagnetic heating and infrared thermal imaging.To investigate heat generation of cracks in ECPT,a metal plate with a through-fatigue crack is considered as the research object in this study;the experimental system and finite element model are established,and the regular method of heat generation for cracks is analyzed.The results indicate that the closer position is to the root of the crack,the greater is the maximum temperature rise for the same duration for the infrared thermal image under consideration;meanwhile,the temperature rise in the crack region gradually increases during the stimulation process,and the temperature rise in the crack region has a gradual decline,and it shows a rapid and slow slowdown..Further,the effect of crack length on the temperature rise in the crack region is revealed.